Metallic-backed tooth.



No. 797,515. PATENTED AUG. 15, 1905. W. G. HUGHES.

METALLIC BAGKED TOOTH.

APPLICATION FILED FEB. 11. 1903.

WITNESSEQ): INVENTOR Mix/4M4 W wbzda UNITED STATES PATENT OFFICE.

Specification of Letters Patent.

Patented Aug. 15, 1905.

Application filed February 11, 1903. Serial No. 142,836.

To all whom it nuty concern:

Be it known that I, WILLIAM G. HUGHES, of Pittsburg, Allegheny county,Pennsylvania, have invented a new and useful Metallic- Backed Tooth, ofwhich the following is a full, clear, and exact description, referencebeing had to the accompanying drawings, forming part of thisspecification, in which- Figure 1 is a perspective view of a toothconstructed in accordance with my invention. Fig. 2 is a similar viewshowing a block of teeth and modified form of plate; and Fig. 3 is avertical cross-section of Fig. 2, taken on a plane passing between twoteeth of the block and showing the tooth material partly in section andpartly inside elevation.

The object of my invention is to provide improved means by whichartificial teeth can be attached to crown bridgework, rubber plates, orother dentures.

The invention consists in an artificial tooth having on its lingualsurface a backing composed of a smooth foil, sheet, or plate of metal,preferably platinum or platinum alloy, which is applied to the toothmaterial and secured thereto solely by baking it on at the hightemperature to which the tooth is subjected in its manufacture. Thesilica or other material in the tooth-body under the action of the heatforms a fused enamel and acts to securely cement the metal to the toothwithout the use of any anchoring projections, rivets, or other securingmeans. When the tooth is to be attached to bridgework, this metalbacking constitutes effective means for soldering to the bridgework orfor attaching to a plate of rubber or the like. WVhen the plates ofappreciable thickness are used, it may be desirableto 'roughen thelingual or outer surface of the plate to assist in securing or solderingthe tooth to the denture; but I have found that light coatings or foilssecured to the toothbody in the manner mentioned are sufficient for mostpurposes and are to be preferred where low cost is essential. Theplatinum backing thus applied affords no space for thelodgment of foodparticles, as do the means usually employed heretofore, and in theprocess of making the tooth the distribution of heat thereto with suchbacking is uniform and the tooth is not apt to crack or check as whenwires or anchoring projections are embedded in it to afiord the means ofattachment.

On account of their greater mass, pins or wires when used conduct theheat rapidly to the point of attachment and often check and cause injuryto the tooth. A smooth metal backing also adds materially to thestrength of the tooth, whereas embedded wires or projections tend toweaken it. Moreover, the color of the tooth is not changed during theprocess of securing it to the denture by heat.

In Fig. 1 of the drawings, 2 represents an artificial tooth made, asusual, of porcelain or feldspar material, and 3 is a platinum plate,sheet, or foil which is secured to the lingual surface.

In Fig. 2 I show a block of teeth 2 with similar plate 3, having a ridgeor projection t formed thereon for attachment to the denture when usedfor crown or bridgework. The platinum backing is pressed on, molded on,or applied in any other preferred manner to the lingual surface of thetooth or block of teeth before baking, and when subjected to the hightemperature employed in baking the platinum securely attaches itself toand forms an integral part of the tooth.

The platinum or other alloy is preferably of such a character that itscoeliicient of expansion and contraction is the same as or as nearly aspossible like that of the tooth material.

Any suitable kind of metal support or denture may be soldered or securedto the platinum backing, or where it is of considerable thickness toadapt it to be embedded in rubber the rear surface of the platinum maybe roughened to afford the required hold.

The plate may be used either on a single tooth or upon a group of teeth,known as a block.

I claim-- 1. An artificial tooth having on its lingual surface a plainmetallic coating secured to said surface solely by the vitrification ofthe tooth material itself; substantially as described.

2. An artificial tooth having on its lingual surface a plain coatingcontaining platinum, said coating being secured thereto solely by thevitrification of the tooth material itself; substantially as described.

3. An article of manufacture consisting of an artificial-tooth structurecomprising a thin metallic plate having a facing of enamel or othersimilar material fused to one side thereof and adapted to be secured toa supporting dental structure.

at. An artificial-tooth sttuoture comprising WTHJIJAM G- HUGHES a thinmetallic plate having a lacing of enamel or other similar material fusedto one side thereof, and a solid metallic body portion se cured to theother side thereof.

In testimony whereof I have hereunto set my hand.

Witnesses:

Gino. B. BLEMING, H. M. COIRWIN.

